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Laser Propulsion and Space Based Solar Power
Keith Henson (L5 Society Founder)
Power down to Earth via lasers.
What does this have to do with Transhumanism?
Running out . . . .
Carbon problems
The Basic Idea
Build one power satellite the hard way.
Equip it with propulsion lasers
Bring up material to build hundreds using the first one.
Build more propulsion lasers as well.
Undercut/displace fossil fuels.
Three years ago
Three weeks ago
What changed?
Google China India Power Satellites
Last week in the news . . .
THE SABRE ENGINE
First SABRE Pre-cooler ModuleThis was manufactured in 2004
SABRE Pre-cooler Demonstration
Can’t be done with chemical fuel
• Current $20,000/kg to GEO
• SpaceX $4,000/kg $1,000/kg
• 20t/1400t, 1.4% payload
• Skylon ~$1000/kg $500/kg
• 7t/300t, 2.3% payload
Hydrogen combustion to 25 km, & Mach 5.5 Laser heated hydrogen
above that point (laser beamed down from GEO)
• 2.3 to 3.4 GW of laser
• Performance analysis, 54 t to LEO
• Vehicle 24 t, (20% structure) plus
• 30 t second stage to LEO
• 2/3rd of second stage to GEO (20 t)
900 s, 6 deg sweep over ~4000 km. 5845 m/s velocity gain on 2.3 GW
GEO
320km perigee
760 s, 11 deg sweep over 6950 km. 2500 m/s velocity gain
270 MW laser source after 5 hrs GEO
Hohmann transfer orbit 5 hr
320km perigee
140 s, 1630 m/s 3670 km
-$160,000
-$140,000
-$120,000
-$100,000
-$80,000
-$60,000
-$40,000
-$20,000
$0
0 2 4 6 8 10 12 14
Years from start
Mill
ion
s o
f d
olla
rs
Growth: 100GW/year, ten percent (10 GW) used for more propulsion,
triples the cargo capacity to 1.5 M t/y, 300 GW/year. Triple that and the
expansion rate is almost a TW/year.
It's possible that humanity could be mostly off fossil fuels in two
decades. (Sandy is a factor.)
End of talk
http://hplusmagazine.com/2012/04/12/transhumanism-and-the-
human-expansion-into-space-a-conflict-with-physics/
BUT—It is too big to do without major government backing
• And oil, coal and gas industries will lobby against a real solution. (Maybe not)
• So why should a government consider backing it?
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Cost
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Cost breakdown
•Vehicle amortization $10/kg
•Hydrogen $6/kg
•Laser $50 B (written off in 5 years)
•$10 B/0.5 B kg is $20/kg
•$36/kg, well under the $100/kg number
•Profit more than $50/kg
Completing 2.3 to 3.4 GW
•$ 34 B laser/power sat parts, 17,000 tons
•60 ¼ scale vehicles, 5 tons to GEO
•20 flights per day, 170 days, 2 years total
•Transport cost @ $100/kg $1.7 B
•Total cost $50-100 B
•Income @ $100/kg * 500,000 t $50 B/yr
•Payback from profit 3-4 years.
Chemical rocket (and planes) can't build power sats but they
can build a large, expensive laser
• 3.4 GW electric power at 2 cent per kWh is worth $480 M/yr
• 3.4 GW of laser propulsion is worth $50 B/yr
• >100 times as much
Part 4This makes a business case
• It closes the business case for making 2 cent per kWh power and we know there is plenty of market at that price (TWs)
• It solves energy, energy security and carbon problems (carbon neutral synthetic fuel for a dollar a gallon)
• Even at two cents per kWh it makes huge profits to support growth.
Simple analysis
• 10 year return on capital, 80,000 hours• $1600/kW can be paid back at 2 cents per
kWh (Below coal to get market share)• $200/kW rectenna, $900/kW parts and labor
($450 before transmission loss), $500/kW for transport to GEO
• At 5 kg/kW requires• $100/kg or less to GEO
It costs perhaps 10% of what a war with Iran would cost
• SDI with the USSR or Russia was/is a losing business.
• It will be decades before Iran could overwhelm a multi GW propulsion laser and by that time the commercial demand for laser propulsion should be in the tens of GW
• Cheap power from space removes any legitimate reason to sort out uranium atoms
Google “henson oil drum” for a slightly out of date “white paper”
on this topic
• Part 1 months ago
• Part 2 and 3 a few weeks ago
• Part 4 last week
• This is unlikely to be the final evolution of the idea.
Why Airdrop at 10 km
• Large Landing gear reduction
• Max landing is 54 tons, 120 t less 76 tons of LH2 dumped in an abort.
OVERALL CONFIGURATION OF GEOSYNCHRONOUS SPS (FROM DOE STUDIES)
SPACEBORNE ARRAY
RECTENNA ON EARTH
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Percent payload (blue)GW x 10 (orange)
Ve vs Payload % and GW (x10) for 6 km/s delta V50 kg/s hydrogen feed, 20% structure
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40 kg, but just scaling from MW to GW, move to Equator, cover mountain with gyrotrons, run 4 minutes out of 20, 11 million
truck batteries, 5 years and they die, but in that time 500 GW of
SBSP. Silly to send power down and back up so . . . .
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Payload percent per GW and $/kg vs Ve for 6 km/s delta V
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105 kW CW
Getting started (Building a seed laser)
• small scale, 500 MW @ 10 kg/kW
• 5000 tons, Falcon Heavy @ 20 t per flight
• 250 flights at 0.1 B/flight, $25 B
• $5 B laser at $10/W
• 500 days at a launch every other day
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